How much does 100 gallons of water weigh?
How much does 100 gallons of water weigh?
Answer
Water is taken at 20 °C (68 °F), where its density is 0.998 kg/L, so one US gallon of it weighs 8.33 lbs. Colder water is a touch denser and weighs slightly more; warmer water slightly less.
In imperial (UK) gallons of 4.54609 L instead of 3.785411784 L, 100 UK gallons of water would weigh 1,000 lbs.
How the weight of 100 gallons of water was worked out
A US gallon is exactly 3.785411784 liters and a pound is exactly 0.45359237 kilograms, so the density in kilograms per liter turns into pounds per gallon by multiplying by the first and dividing by the second.
100 gal × 0.998 kg/L × 3.785411784 ÷ 0.45359237
≈832.9 lbs
(eight hundred thirty-two point nine lbs)
The density comes from FAO/INFOODS Density Database v2.0: liquid water at 20 °C; rounding to 1.00 kg/L is fine for everyday use.
Why the same gallon weighs differently
A gallon measures volume, a pound measures weight, and density is what ties them together: how many pounds one US gallon of this particular substance comes to. Water is the everyday reference at 8.33 lbs per gallon, and everything else sits above or below it.
Across this page the spread is wide: one US gallon of propane weighs 4.24 lbs, one US gallon of milk 8.6 lbs — at the very same volume.
If the substance is not known in advance, start from how many pounds 100 gallons is — the same volume across every substance at once.
The other way round: how many gallons a weight fills
This page starts from a volume and answers in pounds. The opposite question — how many gallons a given weight comes to — is what the pounds to gallons calculator is for, and in metric units the same question is kilograms to liters. All of them read one density table, so their numbers agree.
For water that means 100 gallons weighs 832.9 lbs here, and one pound of it fills 0.12 gallons there.
Related Calculations
See Also
- Pounds to Gallons - How many gallons a pound of water, milk, oil or propane takes — by density
- Liters to Pounds - How much a liter of water, gasoline or propane weighs in pounds — by density
- Liters to Kilograms - How many kilograms are in a liter of water, honey, gasoline, sand and other substances — by density
- Gallons to Liters - Convert US Gallons to Liters
- Lbs to Kg - Convert Pounds to Kilograms
<a href="https://calculat.io/en/volume/gal-to-lbs/100--water">100 gallons of water in pounds — 832.9 lbs at 68 °F - Calculatio</a>
How much 100 gallons of each substance weighs
| Substance | Weight of 100 gallons | One US gallon | Density, kg/L |
|---|---|---|---|
| Diesel | 696 lbs | 6.96 lbs | 0.834 |
| Gasoline | 617.6 lbs | 6.18 lbs | 0.74 |
| Milk | 859.6 lbs | 8.6 lbs | 1.03 |
| Propane | 423.6 lbs | 4.24 lbs | 0.5076 |
| Vegetable oil | 767.8 lbs | 7.68 lbs | 0.92 |
| Water | 832.9 lbs | 8.33 lbs | 0.998 |